<!DOCTYPE html>
<html>
<head>
    <meta charset="UTF-8">
    <!-- import CSS -->
    <link rel="stylesheet" href="https://unpkg.com/element-ui/lib/theme-chalk/index.css">
    <!-- import Vue before Element -->
    <script src="https://unpkg.com/vue/dist/vue.js"></script>
    <!-- import JavaScript -->
    <script src="https://unpkg.com/element-ui/lib/index.js"></script>
</head>
<body>
<div id="app">
    <el-button @click="fun()">Button</el-button>
    <el-dialog :visible.sync="visible" title="Hello world">
        <p>哈哈</p>
    </el-dialog>
</div>
</body>

<script>
    new Vue({
        el: '#app',
        data: {
            visible: false
        },
        methods:{
            fun:function () {
                this.visible = true;
            }
        }
    })
</script>
</html>